Scene and Scenario

The devised scenario for evaluating the developed prototype of this project was to run the server application on a PC located in room A27 of InfoLab21 imitating the server of the Cockermouth Mountain Rescue Team. To imitate the rescue worker’s mobility it was decided that we should roam across campus holding the PDA running the client’s developed application and the external GPS device.

Our Experiment

Client's Log
Server's Log

Server's Video

In order to the above described scenario a specific route was defined illustrated in the Figure above. The server application was set up at a PC located at InfoLab21 and all the listening features were enabled. To be precise, the server was listening to its global IPv4 address and port 10.000 for IP packets being sent either via WIFI or GPRS, and was also listening for SMS messages over its Bluetooth connection with the Nokia 6230i mobile phone.

On the client’s side the application was executed and the GPS functionality was enabled using the external GPS device. Consequently the communication functionality was also enabled and we decided to follow the specific route that is illustrated in the above Figure. Basically, our starting point was at Infolab21, in the room where the server was located, and we decided to walk along the spine till the Chaplaincy Center and then walk back to the InfoLab21 following the road that passes next to the Ruskin Library and the University’s Hotel.


In brief, while we were still inside the Infolab21 the client was sending GPS coordinates via WIFI. While exiting the Infolab21, the application identified that the WIFI signal strength was poor and established a GPRS connection. While we were drewing away the InfoLab21 the application tried to acquire a TCP socket over GPRS and send three SMS messages as there was no WIFI coverage and as the TCP socket over GPRS was not initialized yet. When the application managed to acquire the TCP socket over GPRS it swapped to it and started sending GPS coordinates over it. From that point on, GPS coordinates were sent only via GPRS through the whole route until we reached back the InfoLab21. While entering InfoLab21 the application detected WIFI connectivity disconnected the GPRS connection and tried to acquire a TCP socket over WIFI. During this swapping procedure one SMS was sent and then the application started sending GPS coordinates over WIFI.